camp krystle campbell, for bu grad student lingzi lu, and sean kohl years, the m.i.t. police officer shot and killed in his patrol car thursday night, just are 55 minutes before his shift would have ended. >> he was a great young man. he was wise beyond his years. his goal was always to become a police officer. >> reporter: his family writing our only solace is that sean died bravely doing what he committed to do, serving and protecting others." then there are those still fighting to survive. officials say 33-year-old transit officer richard donohue was shot multiple times during the gunfight with the tsarnaev brothers in watertown, tonight, in serious condition. liz norden's two sons each lost a limb near the finish line. >> it was a nightmare. it's running between two hospitals, trying to be each of them as sick as they are or hurt as they are, it's, i couldn't be in both places at both times. it's a nightmare. >> reporter: today, 31-year-old paul opened his eyes for the first time since he lost his leg. >> well, for a lousy situation, i just thank my lucky stars the